Question

A wire carries a steady current, it is bent
into a ciele of one tum and the magnetic field at the centre of the coil is B. it is then bent into a circular loop of n tums, the magnetis field at the center of coil will be.​

Answer 1

Answer:

The circumference of the first loop is the length of the wire=2πR

The magnetic field at the center of this wire=B=

2R

μ

0

I

The same wire is bent into n circular coils.

Thus new radius is found out by

n×2πr=2πR

⟹r=

n

R

Thus magnetic field at the center of these loops=n

2r

μ

0

I

=

2R

n

2

μ

0

I

=n

2

B